Biochemical effects of lead toxicity on some haem biosynthetic enzymes in rats

Abstract EN

Lead bioaccumulations in the liver and hepatic micro some of rats were studies after 1, 3, 7, 14 and 28 days daily of intraperitoneal injection of 10 Ilmolj kg body weight.

In addition, the relationship between the bio accumulated lead in both hepatic micro some and the liver and their harem biosynthetic enzymes were studied.

Pretreatment of rats with intraperitoneal injections of lead was shown to result in a depression of the micro small mixed function oxidase system, as assessed by a decrease in hepatic microsomal cytochrome P-450 and bs content and by a decrease in the activity of the enzymes aniline hydroxylase and aminopyrine demethylase.

Lead had a more marked effect on cytochrome P-450 than bs.

The activity of the rate-limiting enzyme of harem biosynthesis, o-aminolaevulinic acid synthase, was inversely correlated with the microsomal cytochrome P-450content.

The activity of the ham biosynthetic enzymes o-aminolaevulinic acid dehydratase, coproporphyrinogen oxidase and ferrochelatase were decreased by increasing lead pretreatment.

The activity of the harem catabolic enzyme, harem oxygenize, was increased by lead pretreatment.